1. Field of the Invention
The present invention relates generally to a method and an apparatus for assembling automobiles and, more particularly, to a method and an apparatus for assembling a wheel to a vehicle body.
2. Description of Related Art
Conventionally, in vehicle assembling lines, a wheel assembling apparatus is used to adjust angular positions of hub bolts with respect to bolt holes of the wheel hub, insert the hub bolts into the bolt holes and fasten nuts to the hub bolts all at once so as to assemble a wheel to a vehicle body. Such an automatic wheel assembling apparatus is known from, for instance, Japanese Patent Publication No. 4-80,777.
If such a vehicle assembling line is adapted to assemble different types of vehicles, the automatic wheel assembling apparatuses have to handle different types of wheels corresponding to the different types of vehicles. However, because bolt holes of the wheel hubs are different in angular position according to type, the conventional automatic wheel assembling apparatus is not readily adaptable to vehicle assembling lines in which different types of vehicles are assembled.
An automatic wheel assembling apparatus, such as a robot hand, is apt to change its controlled position due, for example, to aging. It is necessary, therefore, to confirm the accuracy of position control of the robot hand at a proper time. The accuracy of position control of the robot hand depends upon the setting of a work origin.